1. Technical Field
The present invention relates to techniques for ejecting liquid from an ejection nozzle.
2. Related Art
Liquid ejecting apparatuses that eject liquid such as ink from an ejection head in which fine ejection nozzles are provided are known. With such a liquid ejecting apparatus, the liquid to be ejected (ink, for example) is held in a dedicated receptacle (an ink cartridge, for example), and the liquid within the receptacle is ejected by supplying that liquid to the ejection head via a flow channel.
Meanwhile, there are situations where sedimentary components are used as components in the liquid to be ejected. For example, in the case of ink, pigments are used in order to increase the so-called climate resistance or improve the color development properties of the ink. Because pigments are suspended rather than dissolved within the carrier (water, alcohol, or the like) of the ink, a pigment will settle within the carrier if the ink is left standing for an extended period of time. As a result, areas of high pigment density and areas of low pigment density occur within the ink, which makes it impossible to print images properly.
Accordingly, a technique has been proposed for an ink jet printer that includes ink containing sedimentary components (called “sedimentary ink” hereinafter) in which, when it has been determined that settling has occurred in the ink within an ejection head, the ink in which the settling has advanced is discharged by sucking the ink from an ejection nozzle (JP-A-2002-234196 is an example of related art.).
However, the settling of components contained within the liquid (ink or the like) to be ejected occurs not only within the ejection head, but also within the flow channels that supply the liquid from the holding receptacles to the ejection head. Although settling occurring in the flow channels does improve to an extent by the time the liquid has passed through the flow channels and reached the ejection head, there are cases where the settling has advanced to a point where it cannot be corrected; in such a case, it is necessary to discharge not only the liquid within the ejection head, but also the liquid within the flow channels, which is problematic in that a large amount of liquid is wasted. In particular, with a type of liquid ejecting apparatus in which a dedicated receptacle that holds the liquid is provided in a location that is far away from the ejection head and the liquid is supplied to the ejection head via a long tube or the like, a large amount of liquid is present within the tube and must be discharged, and thus the stated problem is even more marked.